Stair construction



E. HEDEEN STAIR CONSTRUCTION Sept. 18, 1928.

Filed Aug. '25, 1927 INVENTOR lg bnerfz w j am.

ATTRN EY S Patented Sept. 18, 1928.

UNITED STATES 1,684,765 1? AT ENT QF C ELMER HED'EEN, 0F MANSFIELD, OHIO, ASSIGNOR TD HUGHES-KEENAN'QO M- PANY, 0F MANSFIELD, OHIO, A CORPORATION OF OHIO.

STAIR CONSTRUCTION.

Application filed August 123, 1927. Serial No. 214,955.

Fig. 3 is a detail showing how the parts are assembled.

Referrin more s "ieciticall f to the draw- *r lugs, there is shown a pair of stringers 5 sup porting the steps, each stringer being preferably of sheet metal and having an inturned flange (3 along its underside. The steps proper, which embody the improvements rest partly on the two flanges 6 and partly on tie rods 7 passing through the stringers and'binding them together, as will be described.

The steps are built up from a series of interlocking sheet metal elements each having a length equal to the distance betweenthe stringers and each being bent at right angles to provide a horizontal tread or tread-supporting portion 8 and a vertical riser portion 5) with the corner or angle 10 secured at opposite ends by belts or screws 11 to the flanges (l. The sheet metal step elements are interlocked at the front of each tread, the interlocking being accomplished at the time the stairway is installed, and preventing any relative lateral or up and down movements of the step elements. Longitudinal movements are prevented by the stringers. The interlocking is permitted because of the shape of the parts and the way they are assembled, and is accomplished without employing any movable fastening parts, hence without any labor other than the inevitable labor of bringing the parts together. The elimination of this labor results in a rapid building of the stairway, thusincreasing the profits of the builder, and facilitating completion of the job.

As shown, each tread ortread-supporting portion 8 is substantially plane except at the forward edge, where an upstanding flange 1,2 is provided, as by bending. The upper end of each riser portion 9 is bent to provide a flange 13 which is vertical andoflset relative to the riser portion, being located in front of the plane of the riser. At its upper edge, each r ser flange 13 is bent rearwardly shbstantially at right angles, as at 14, not only to enclose the flange 12 of the adj acent tread portron 8, but also to protect the tread andiaid in holdi it, and also to carry means forinterloclring with the adjacent flange 12. I

As shown, each flange 14 carries on it-s'un derside a rod 15 providing a bead, spaced a small fraction of an inch from flange 13, and secured as by spot welding 16. As the. flange lit is slightly taller thanflange 12, the latter will be received between the flange 14': and the 110112 ntal oflset portion 17, permitting manual is einbly of the step elements, as shown in Fig.

With the parts assembled as in Fig.1, it will be clear that any stress tending ti) separate any two interlocked step elements will be resisted. by contact of the bead 15 with flange 12, which is stil'l'ened by flange 13. The treads are carried by the tie rods '7. the offset portions 17 and the flanges 6. Any tendency of the treads 8 to yield under loads results in a very slight rocking on tie rods 7, thrusting the flange 12 "up against flange 14,-, which tends to pull up the riser portion of the lower stop element. Most of the loatL on each trend is transferred directly to the tie rods 7. which are of adequate strength, )articularly when tightened to the stringers by their nuts 18. T tie rods subject the step elements. particularly at the joints, to a-compressive stress, thus contributing to the rigidity and strength. of each oint. The bead 15 also plays a partin stif ening the flange 14, which cannot bend downwardly under load to any appreciable extent because of the adjacent i'langes 12., 13. It will be clear that flange 1d eliminates a nosing insert. 1

The treads 19 may be of any material, and as shown are so placed as to be supported by the tread-supports 8, and so as to be confined between and subjected to compressive stresses from the stringers 5. The treads may be positioned either before or after erection of the stairs, according to the material they are made of, and when in position, serve to reinforce the tread supports as well as to brace the flanges 12, 13 and the interlocked joint. Obviously, the flanges 14- will aid in holding the treads 19.

Obviously the present invention is not re stricted to the particular embodimentthereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

WVhat I claim is 1. A sheet metal element for the construction of stairs, comprising a tread portion and a riser portion; an upstanding flange extending longitudinally along the outer edge of the tread portion substantially at right angles thereto; an inturned flange provided at the upper end of the riser portion to project somewhat over the tread portion of the adjacent stair element; and a bead made fast underneath said inturned flange so spaced from the vertical plane of the adjacentriser portion that there is suflicient c room to receive the upstanding flange of the adjacent, higher stair element.

, 2. A sheet metal element for the construction of stairs, comprising a tread portion and a riser port-ion; an upstanding flange extending longitudinally along theouter edge of the tread portion substantially at right angles thereto; an ofiset flange provided at the upper end of the riser portion and joined thereto by a. shoulder which aids in the assembly and support of the adjacent, higher tread; an inturned flange at the upper edge of said oifset flange; and a rod spot-Welded underneath said inturned flange-to hold the upstanding flange of the adjacent, higher step element, when the stairs are assembled.

In testimony, that I claim the foregoing as my own, I have hereto aflixed my signature.

ELMER HEDEEN. 

